Zeta Model

The Zeta Model software is one of the two primary components that comprise the Zeta Safety System for well intervention operations. The Zeta safety system utilizes data and modeling to eliminate the guesswork commonly associated with well intervention design and operations. Designed to avoid catastrophic buckling and bending failures of well intervention stacks, the Zeta Safety System consists of a real-time monitoring gauge and an advanced job design model for well intervention operations.These potential failures are costly and could involve human injury and unplanned release of wellbore pressure to the atmosphere.

The Zeta model is based on a non-linear finite-element (FEA) approach, purpose-written for analyzing intervention structures. The FEA analysis is run repeatedly at very small time increments to perform a dynamic analysis. A finite difference, forward difference scheme is used to determine the acceleration of each component in the stack, and the associated dynamic forces. The model accurately calculates the buckling instability of the stack. It also calculates the Von Mises stress throughout the structure, and compares the guy-wire loads to user-defined limits. Thus, it examines the structure for both modes of failure: failure due to buckling instability and failure due to yielding of a component in the structure.

The Zeta Model answers the following questions:

Stress levels for the entire well intervention stack

Accurate modeling of stacks with moving wellheads and or floating platforms (dynamic analysis)